Use overlay2 in tools/setup_Redhat.sh

Currently CentOS gates use btrfs storage driver and
create /docker device backing btrfs.

This patch is to sync the gate run with Ubuntu.
(post-Trusty) does not use btrfs, only overlay2.

Change-Id: Ic5caa8cf0271b21f71f03fd33c35b3c7bc93ccf4

tools/setup_RedHat.sh

@@ -3,54 +3,6 @@
 set -o xtrace
 set -o errexit
 
-function setup_disk {
-    if [[ -f /etc/nodepool/provider && ! -f /swapfile ]]; then
-        sudo swapoff -a
-        sudo dd if=/dev/zero of=/swapfile bs=1M count=4096
-        sudo chmod 0600 /swapfile
-        sudo mkswap /swapfile
-        sudo /sbin/swapon /swapfile
-    fi
-
-    if [ ! -f /docker ]; then
-        sudo dd if=/dev/zero of=/docker bs=1M count=25600
-        sudo losetup -f /docker
-        DEV=$(losetup -a | awk -F: '/\/docker/ {print $1}')
-    fi
-
-# Excerpts from https://github.com/openstack-infra/devstack-gate/blob/dc49f9e6eb18e42c6b175e4e146fa8f3b7633279/functions.sh#L306
-    if [ -b /dev/xvde ]; then
-        DEV2='/dev/xvde'
-        if mount | grep ${DEV2} > /dev/null; then
-            echo "*** ${DEV2} appears to already be mounted"
-            echo "*** ${DEV2} unmounting and reformating"
-            sudo umount ${DEV2}
-        fi
-        sudo parted ${DEV2} --script -- mklabel msdos
-        sync
-        sudo partprobe
-        sudo mkfs.ext4 ${DEV2}
-        sudo mount ${DEV2} /mnt
-        sudo find /opt/ -mindepth 1 -maxdepth 1 -exec mv {} /mnt/ \;
-        sudo umount /mnt
-        sudo mount ${DEV2} /opt
-        grep -q ${DEV2} /proc/mounts || exit 1
-    fi
-
-    # Format Disks and setup Docker to use BTRFS
-    sudo parted ${DEV} -s -- mklabel msdos
-    sudo rm -rf /var/lib/docker
-    sudo mkdir /var/lib/docker
-
-    # We want to snapshot the entire docker directory so we have to first create a
-    # subvolume and use that as the root for the docker directory.
-    sudo mkfs.btrfs -f ${DEV}
-    sudo mount ${DEV} /var/lib/docker
-    sudo btrfs subvolume create /var/lib/docker/docker
-    sudo umount /var/lib/docker
-    sudo mount -o noatime,subvol=docker ${DEV} /var/lib/docker
-}
-
 # (SamYaple)TODO: Remove the path overriding
 export PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
 
@@ -63,14 +15,12 @@ sudo yum -y install libffi-devel openssl-devel docker-ce btrfs-progs
 # Disable SELinux
 setenforce 0
 
-setup_disk
-
 # Setup Docker
 sudo mkdir /etc/systemd/system/docker.service.d
 sudo tee /etc/systemd/system/docker.service.d/kolla.conf << EOF
 [Service]
 ExecStart=
-ExecStart=/usr/bin/dockerd --storage-driver btrfs --insecure-registry=0.0.0.0/0
+ExecStart=/usr/bin/dockerd --storage-driver overlay2 --insecure-registry=0.0.0.0/0
 MountFlags=shared
 EOF